Memory card erasure


New Member
I am considering selling a camera along with several Compact Flash and XD cards:as I have no wish for a buyer to open all my family and holiday photos I'd like to securely erase each card.
The cards have already been re-formatted but I can at present recover files using Recuva.
I have tried to erase using Eraser but failed: this is the first time I have used the program.

Can anyone give me the correct sequence of actions to achieve success.

Tried to date:
New Task > Add Data > Files in Folder: uncheck Erase Folder if empty > Browse > Removable Disk (I:) > Tasks execute manually > (I:) right click > run now.

When this failed I thought OK, no files visible, so I used > Unused Disk Space > Disk (I:), checked Erase Cluster Tips > Run now. I got message to run as Administrator.

Closed Eraser > Right Clicked the Program > Clicked Run as Administrator and repeated the last (Unused space) action. I still had the same message 'to run as Administrator'.